/Engine/Source/Runtime/Engine/Classes/Engine/Engine.h
Tries to find the currently active primary Game or Play in Editor world, returning null if it is ambiguous. This should only be called if you do not have a reliable world context object to use.
either nullptr or a World that is guaranteed to be of type Game or PIE
[UWorld](API\Runtime\Engine\Engine\UWorld) * GetCurrentPlayWorld ( [UWorld](API\Runtime\Engine\Engine\UWorld) * PossiblePlayWorld ) const